Washington, April 17 (RFE/RL) - The U.S. State Department says a huge military complex under construction in the Ural mountains is probably for defense purposes and does not violate U.S.-Russian arms agreements.

A State Department spokeswoman, Julie Reside, says the matter has been discussed with Russian officials. "They have not told us the purpose of the facility but we believe it is defense-related," she said.

Reside was commenting on a U.S. press report Tuesday of a secret military project inside Yamantau mountain in the Beloretsk area of the southern Urals.

The report in the New York Times raised the question of whether the Russian government is taking advantage of U.S. military assistance to subsidize Russia's own military programs.

Reside says Russia is carrying out some military modernization of its armed forces, using its own resources. "But these are much more limited than they have been in the past," she said.

"We expect Russia's nuclear and conventional programs to continue to decline in the future," she says.

On that basis, Reside says the U.S. will continue to provide funds to Russia to dismantle nuclear arsenals and safeguard against nuclear proliferation.

The U.S. agreed to give Russia more than 600 million dollars in 1995 under the so called "Nunn-Lugar" program to help dismantle nuclear weapons and build a storage facility for fissile material. In addition to the 1995 commitment, Russia is to receive 150 million dollars from the Nunn-Lugar fund this year.

But one of the conditions imposed by the U.S. Congress, which controls the U.S. budget, is that Russia refrain from taking on new military projects going beyond defense requirements.

U.S. officials say the secrecy surrounding the Russian government's project in the Urals makes it difficult to justify to the U.S. Congress the need for U.S. military assistance to Russia.

White House spokesman Brian Cullin said Tuesday that the U.S. is asking the Russian government for more information about the project. He said the Russians so far have not provided details nor have they disclosed the purpose of the massive installation.

At the Pentagon, as well as the State Department, officials played down the threat of the unknown facility and stressed continuity in benevolent U.S. policy toward Russia.

Reside said "the U.S. believes strongly that the investment in the Nunn-Lugar program to dismantle and destroy Russian nuclear weapons is in the U.S. national interest."

At the Pentagon, spokesman Michael Doubleday said Anericans have known about the Ural project for several years, followed reports about it in the Russian press and continue to watch it closely.

Russian reports say the installation is mostly inside the mountain and covers a vast area, roughly the size of the city of Washington - about 75 square kilometers.The project is believed to have begun more than 15 years ago.

Doubleday said several thousand workers are employed at the construction site and live there in special housing. An extensive rail and road network has been built to serve the site.

The New York Times article, quoting a report in Sovetskaya
Rossiya, said there are towns for tens of thousands of workers and their families.